kolmogorov_smirnov_cdf

  KOLMOGOROV_SMIRNOV_CDF (X, TOL)
  Return the CDF at X of the Kolmogorov-Smirnov distribution,
            Inf
    Q(x) =  SUM    (-1)^k exp(-2 k^2 x^2)
          k = -Inf
  for X > 0.

  The optional parameter TOL specifies the precision up to which the
  series should be evaluated;  the default is TOL = `eps'.

  Ported from octave 2.1.35